Quicktime Export gone!

Wow, that's ... unusual.

Could you make a screen-grab of the Export dialog's Format drop-down list as you're seeing it? Use the Picture icon in the reply box formatting bar to add it into your reply so we can all see it.

Neil

you're probably not gonna want to hear this, but you should have a bootable clone of your startup drive BEFORE you do any OS updates so you can restore your system to it's previous state and get back to work relatively quickly.  Happy to help you with this workflow if you're interested.   

But in the meantime, let's see if there are any possible workarounds. 

Have you tried sending your export to Adobe Media Encoder via the Queue option?  Is the quicktime option available there?  If not, can you create a new preset and access quicktime there?

If it's an apple/adobe problem, you might try installing BlackMagicDesigns DaVinci Resolve and see if you can access a quicktime export from there?  It's a very different interface than premiere.  I think it's in the deliver panel...  

It is possible that your export might have been a QuickTime 7-era (32-bit) codec that you used. Apple began completely depreciating all of its 32-bit QuickTime codecs starting with Mojave, with the total discontinuance of such support coming with Catalina.